Process and machine for long lip bags



Feb. 11, 1936.

G. W POPPE PROCESS AND MACHINE FOR LONG LI P BAGS 6 Sheets-Sheet 1 Filed Aug.

INVENTUR GEORGE M POP/ f Feb. 11, 1936. G W. POPPE PROCESS AND MACHINE FOR LONG LIP BAGS Filed Aug. 8, 1 6 Sheets-Sheet m; MEI/r M NH Feb. 11, 1936. G. w, POPPE 2,030,118

. Filed Aug. 8, 1951 6 Sheets-Sheet 5 BY {24 ATTORNEYS G. W. POPPE Feb. 11, 1936.

lNV OR M OPPf ATTORN EY5 Feb, 11, 1936. W POPPE 2,030,118

Filed Aug. 8, 1931 6 Sheets-Sheet 5 Feb. 11, 1936. G. w. POPPE PROCESS AND MACHINE FUR LONG LIP BAGS Filed Aug. 8, 1931 6 Sheets-Sheet 6 INVENTOR GEOXGE h/ POP/ f I I I I I WWWWWWV I l I I l I I I I I l I I i I l l I I I 1 mum/VII -incila fA/l g BY ATTORNEY Patented Feb. 11, 1936 PRQECIESS AND MACHINE FOR LONG LIP'BAGS George W. Poppe, Brooklyn, N. Y., assignor to Equitable Paper Bag Co. Inc., Brooklyn, N. Y., a corporation of New York Application August 8, 1931, Serial No. 555,893

Elaims. (Cl. 93l8) This invention relates to a process and machine for making paper bags having a closing lip or flap of more than usual length.

The object of the invention is the making of a 5 bag with a long lip on an ordinary bag machine by slight changes and modifications of the usual mechanism found in such machines.

An important feature of the invention resides in forming the bag lip by successive cuts transm verse of the bag tube instead of by simultaneous transverse cuts as is the usual custom. As a corollary to this feature a slack is created in the bag tube to permit the angle of severance of the knife edge to be suinciently large to pro- 1 duce an efiective cut. As a further corollary,

one of the so-called pinch bars is slightly modified to permit a slippage of the free end of the bag tube whereby the desired slack is created.

Another feature of the inventionresides in a supplemental pasting element for the more effective sealing of the bag bottom. I

A further feature of the invention relates to an improved presserfoot construction to permit a smaller bottom than can be efiectively produced by methods heretofore known. Further features relate to a modification of the former or the slitter knives, or both.

Various other features and advantages will become apparent from the following description and claims when taken in connection with the accompanying drawings in which:

Figure 1 is a plan view of the machine; Figure 2 is a section on the line 2-2 of Figure 1; Figure 3 is a detail showing a modified form of slit;

Figure 4 is a detail of the slitter: knife for making the kind of slit depicted in Figure 3;

Figure 51s a detail showing a modification of the lower feed rollers;

the former;

Figure 7 is a former of usual construction;

Figure 8 is an enlarged view of a portion of the mechanism near the center of the machine and shows the position the parts occupy just at the moment when the lower wall of the bag tube is being severed;

Figure 9 shows the same parts at a somewhat later stage of the operation; Figure 10 shows the same parts at a still later stage in the operation;

Figure 11 is a prospective view of the upper pinch bar shown in Figs. 1, 2, 8, 9 and 10;

Figure 12 is a verymuch enlarged view of a portion of a periphery of the two pinch bars show- Figure 6 is a detail of the left-hand end of.

ing a slightly different form of pinch bar from that shown in the preceding figures;

Figure 13 is a similar enlarged View. showing a still diiferent form;

Figure 14 is an elevation of a portion of a periphery of the cylinder which carries the paste bar and presserfoot;

Figures 15, 16 and 17 are diagrammatic views showing the progress of the paper web through the machine and various stages of the bag during its process of manufacture; and

Figure 18 is a diagrammatic view of a further modified arrangement of pinch bar mechanism.

Paper bags made from a bag tube have long been used and high speed machines have been developed for their production. A web of paper is folded over a former to form a bag tube, which tube is then severed by what is known as chopping, and in machines for bag-making a striker bar strikes the bag tube from below and severs both walls against the serrated edges of knives, one serrated edge being carried by the end of the former,v the other knife being a slight distance in the rear. These bags are made without waste, since the closing lip of one bag is cut out of the wall that will form the bottomof the succeeding bag.

In my Patent No. 1,798,168, March 31, 1931, I

have disclosed a process and machine for making paper bags having a closing flap of greater length than is possible with bags made upon machines of the ordinary type. In order to make such a bag as described in said patent, preliminary cuts or slits are made in the web of such a length as to determine the length of the closing lip or flap and the knives are spaced apart a distanceequal to the width of the flap. In the machine of said patent, the striker bar severs both walls of the bag simultaneously.

By the process and machine of the present invention I am enabled to produce 'a bag of the type disclosed in my patent above mentioned, which bag has a very much longer closing flap or lip than the bag produced according to the machineand process of said patent, since the length of the closing flap in the patented con-- struction is limited by the distance which separates knife edges which sever the bag tube transversely. v

In the present invention the transverse cutting edges, although spaced apart no greater distance than in the bag-machine shown in said patent, may nevertheless be employed in a manner to make a much longer lip due to the fact that in my new process the'transverse cuts are not made simultaneously but are made successively and there is a feeding of the bag tube between'successive cuts. In the present invention, preliminary slits or cuts are also made in the web similar to those described in my said patent, except that such slits are much longer.

With the above preliminary explanation of the general ,nature of the invention, it will be in order to describe the process and machine more in detail.

Referring to the drawings, and more specifically to Figure 2,, there is a supporting framework 2, the side members of which support various shafts for driving the usual mechanism of a bag machine. Referring to Figure 1, the motor 4 has its shaft provided with a pulley 5 connected by a belt 6 to a pulley 1 on a shaft 8. This shaft also carries a pulley 9 over which passes a belt l0 connected to a pulley II on the shaft l2. See also Figure 2. A tension roller I3 is also provided to keep the belt l0 sufficiently taut. The shaft [2 carries a gear which meshes with a similar gear on a shaft 14. The shaft l4 carries a sprocket for engagement by a sprocket chain 15 passing over a similar sprocket on a shaft l6 at the upper rear portion of the machine.

The paper from which the bags are to be formed is fed as a web l8 from a roll of paper l9 supported on a shaft 20 in the lower portion of the rear framework. The web passes over a guide roller 25 and around another roller 26 which reverses its direction of movement, the latter roller being carried by a shaft 21. As the web passes about the roller 26 paste is applied from a paste pot 28 into which dips a narrow disc 29. The web of paper, after passing the roller 26 is delivered to mechanism which folds it into a bag tube. This mechanism is of the usual and ordinary type and includes a former plate 30, the right-hand end of which as shown in Figure 2 is bent upwardly at an angle of about 45. The former is supported from a cross-bar 3| carried by arms 2| projecting forwardly'and upwardly as a portion of the framework 2. The paper web passes under the former plate and is folded over on to it, as clearly indicated in Figure 1, rollers 32 carried by arms 33 aiding in making the fold smooth. The folded tube then passes between upper and lower pairs of feed rollers 34, the former being notched as at 34a, Figure 7, to permit the rollers to engage the tube.

The lower rollers 34 are mounted on a shaft 35 which is geared to shaft 8 in the following manner: The shaft 35 is provided with three stepped gears 36 and the shaft 8 is provided with a wide-faced gear 31. An intermediate gear 38 is carried by a swinging arm 39 about the rod 40, and. different surface speeds of the feed rollers 34' to vary the bag lengths may be obtained by meshing the gear 38 with different ones of the gears 36, the wide-faced gear 31 being constantly in mesh with gear 38. one end remote from the gears 36 a gear which meshes with a similar gear M on a shaft 43 which carries the upper feed rollers 34, which feed rollers are supported by a bracket designated generally as 42, and having, as usual, means for varying the pressure of the feed rollers against the bag tube. This bracket also supports a knife 44, shown in'Figures 2, 8 and 9, and is of the usual construction, and is formed with a serrated edge. The end of the former 38 is also provided with a serrated edge 45, Figures 2 and 8.

The shaft 35 carries at So far the machine is similar to that of a bag machine of ordinary construction.

In said ordinary machine and also in the machine disclosed in my said patent, the bag tube is severed into individual bags immediately after passing the feed rollers 34 and this is accomplished by momentarily retarding the web by members known as pinch bars, the walls of the tube being simultaneously severed at the time of retardation.

The pinch bars as ordinarily used and as are shown in my aforesaid patent each have a projection in their periphery which consists of a short segment which momentarily grip the folded web of paper between them and since the peripheral speed of these pinch bars is less than the peripheral speed of the feed rollers, the bag tube is momentarily retarded.

In the present invention the pinch bars are modified in a manner'now to be described in order to enable a long lip to be made.

The lower pinch bar, may have a segment projecting from its circumference, as in my aforesaid patent, or it may consist of a cylinder 46 having a smooth surface as shown in Figures 8, 9 and 10.

The cylinder 46 is provided with a gear 41, Figure 1, which meshes with a gear 48 immediately above it carried by a shaft on which is mounted the upper pinch bar 50. This pinch bar is of special construction to enable it to cooperate with the lower roller 46 to retard the progress of the bag tube at two stages and to permit slippage of the free end of the bag tube during the interval between retardations.

Before further describing the details of this pinch bar construction, the general operation of the mechanism for forming the bag bottom will be described, Since the relations between it and the pinch bar mechanism is important to a full understanding of the invention.

Referring to Figures 1 and 2, the shaft 8 also carries a large gear 52 which meshes with an intermediate idler 53 carried on an arm forming part of a frame to be referred to later. The gear 53 meshes with a gear 54 on shaft 55 which supports the lower cylinder 56 carrying the usual clamp for receiving the bag bottom fold. These parts and their mode of operation will be described later more in detail but for the present it will be necessary only to note that while the transmission of drive from the shaft 8 to the shaft 55 is at a one-to-one ratio, the diameter of the cylinder 56 and its cooperating cylinder 58 is greater than the effective diameter of the pinch bars and consequently, as soon as the tucker blade which is carried by cylinder 58 engages the severed bag, the movement thereof is immediately speeded up. The cylinder 56 is geared to the cylinder 58 in a one-to-one ratio so that the two rotate with the same peripheral speed but in opposite directions.

The special pinch bar construction will now be described and this may best be done by following the operation of the bag tube through its various stages. The pinch bar 50 is shown in perspective, Figure 11, as a segment set into the upper pinch bar roller. The pinch bar has two surfaces in the form of arcs 60 and 62 whose radii are equal to that of the cylinder 46. Consequently, when these arcs are in contact with the bag tube and press it against the roller 46, said tube is retarded during the time of such contact. Between the arcs 68 and 62, however, the pinch bar is cut away or relieved so that it does not press the bag tube against the roller M or at least not with suflicient force to retard it but during this interval the tube may slip if force is applied to it.

Referring now to Figure 8, it will be noted that the bag tube has reached that stage in its advance when it is retarded by the arc 60 of the pinch bar. At this moment of retardation the lower wall of the bag tubeis severed against the serrated edge 45 of the former 30. This severing is effected by one or another of two striker bars 66 which are of the usual construction and are carried on a sprocket chain 65 carried by upper sprocket wheels 66 and lower sprocket wheels 61, Figure 2. It will be noted from this figure, however, that the sprocket chain has more of its travel above the plane of the bag tube than below, the purpose of which is to permit of clearance between the bag tube and the striker bar which is descending, the two striker bars being spaced equal distances apart in the travel of they sprocket chain 65. It will also be noted from Figure 8 that the upper wall of the bag tube is not at the proper angle in respect of the knife edge M to permit of severance at this time, even if severance were desired. It is to be understood, of course, that the bag tube is provided with slits near the edge thereof, these being indicated at 68, Figures 1 and 15. These slits may be formed in any well-known way, as for instance by slitter knives l carried by the shaft 56 which knives may be of the construction shown and described in my Patent 1,798,168, previously referred to. A modification, however, of these knives will be later described in connection with the present long lip bag.

Referring again to Figure 8 the distance apart of the cutting edges it and i5; is less than the length of the bag lip as determined by the slits 68. Therefore it is necessary to permit further feeding of the bag tube after the severance of the lower wall and before severance of the upper wall. Immediately after the severance of the lower wall as shown in Figure 8, the arc t8 passes from the position shown in Figure 8 toward the position shown in Figure 9 and during this time, the bag tube is being fed by the feed rollers 3 Also the striker bar M is moving upwardly. Just as soon, however, as the are 60 relieves pressure on the bag -tube sufliciently to permit it to slip, the striker bar 6 causes the motion of the free end of the tube to be reversed. In Figure 8, for instance, the feeding of the bag tube is indicated by an arrow pointing toward the left and the end of the bag tube is indicated at H. In Figure9, the striker bar 64 has moved to the position there shown and has pulled the tube in the opposite direction, as indicated by the arrow and the end H is displaced somewhat towards the right. The combined action of the striker bar and feeding by the rollers 34 produces a slack indicated in Figure 9. The slippage, however, is out momentarily prolonged.

In order to permit reverse movement of the bag tube the cylinder 58 is cut away along a sufficient arc as indicated at 58a, Figures 8, 9 and 10.. c

The next step in the operation is depicted in Figure which shows the pinch bar to havemoved just beyond the position where the bag tube is pinched by the arc 62. Just prior to the parts reaching the position shown in Figure 10, the bag tube has been pinched by the are 62 and at that moment the striker bar 64 acts to sever the upper wall of the bag against the knife 44. It will be noted at that time that the angle which the upper wall of the bag tube makes with the cutting edge M is nearly a right angle and gives a very easy and efiective cut. The relation between the speed of the rollers 34 and the speed of the striker bar 64 is important and it is necessary that the speed of the striker bar be considerably greater than the feeding speed of the rollers 3% in order that severance may occur. This feature is likewise true in the making of an ordinary bag.

The length of the bag lip is substantially the distance between the striker bar 64 and the edge 44 as shown in Figure 10. In this figure it will be noted that the edge of the lower wall 'of the bag is just about at the edge of the striker bar. The arc 62 has at this time freed the bag and it has been completely severed from the tube, when the parts are in the position shown in Figure 10.

The tucker blade engages it at this time and it is pulled rapidly towards the rear just as the rear striker bar 66 is descending so that it may pass by the top of the bag without causing any trouble.

The cylinder 58 has been referred to generally and it will now be described more in detail. It carries a tucker blade l2 which is of the usual and well-known construction. This blade coopcrates with a clamp id in the'lower cylinder 56, the two cooperating to make the fold in the bag bottom, in the well-known way.

In the present application the details of the mechanism for operating the clamp id have not been shown in great detail but in Figures 9 and 10 its operation can be readily followed. The clamp is carried by a rod Ma rotatably mounted in a box bearing Mb set into the cylinder 56. An arm '55 is attached tov rod Ma and carries a roller it which engages a cam ll which causes the clamp to be closed and to receive within it the tucked in end of the bag bottom.

The cylinder 58 also carries a paste bar It attached to a bar 80 running longitudinally of the cylinder. The paste bar usually consists of a brass strip and in the present instance it is shown as secured in the bar 88 by screws, one of which is shown as 82 in Figures 8 and 9. The paste bar is moved in and out a short distance by a cam shown in dotted linesat 863, Figure 9, said cam engaging a roller 85 secured to a shaft 86 which carries at either end an arm 8? which arms engage rollers 8M mounted on the bar 80. This paste bar operatingmechanism is of old and well-known construction and therefore has not been shown in detail in the present disclosure. It should be stated, however, that the cam 84 is of such contour and is so positioned that the paste bar is withdrawn immediately after the line of paste has been applied to the bag bottom; Such withdrawal is necessary 'to prevent interference with the lower cylinder. However, immediately after the cylinder 58 has rotated sufficiently to take the paste bar out of the zone of the paper, the paste bar is moved by springs to a projected position ready to contact with the paste applying roller 88, rotatable in a recess in a paste pct 90, Figure 2.

In the machine of the present invention two auxiliary paste-applying devices 92 are adjustably secured to the bar 80 as shown in Figures 8, 9, l0 and 14. Each of these devices consists of a bent bar of small diameter and having a pasteapplying end 94 by which a small spot of paste is applied to the gusset of the bag bottom as ,will be more particularly described later on.

The cylinder 58 also carries a presser foot 96 which engages the bag tube at the proper time to prevent the upper wall of the tube from following oration may be fully appreciated, reference is bar 18 is indicated at mo.

- clamp by the tucker blade.

made to Figures 15, 16 and 17 which show diagrammatically the formation of a bag from the web. The upper part of Figure 15 shows a portion of the web just after it has passed around the roller 26 and prior to the folding of the same to form the bag tube. A line of paste 98 has been applied by the roller 29. As the web passes under the former plate it is folded over and the seam is smoothed down by the rollers 32 as previously described. The slots Bil-have been formed by the slitter knives 19, Figure 2, the tube then passing to the chopping mechanism which forms the long closing flap by the means which have already been described in detail. By reason of the fact that the slits 68 slant inwardly there are formed near the bottom of the bag what may be called gussets 99 at each side thereof.

My said application 537,844 describes a machine and process for making a bottom fold which is lower than iscustomary in paper bags. In the present invention the same mechanism is employed and for that reason the presserfoot arrangement above referred to and shown and claimed in said application is used. Referring to Figure 16 the line of paste applied by the paste The line of fold is indicated at a-a. In other words, the tucker blade 72 contacts with the bag along the line a--a. It will be noticed that the bottom of the bag is quite large due to the fact that the portion cutout is of the same size as the upper or closing flap. It is therefore desirable in such a bag that the bottom fold may be made as small as possible consistent with proper sealing of the bottom. From Figure 16 it will be observed that that portion only of the upper wall which in-v cludes the gussets 99, is inserted within the The upper wall proper of the bag is not tucked in and hence there is danger of the upper wall following the paste bar as the paste bar is withdrawn, resulting in damage to the bag or to improperly folded bottoms. The presserfoot therefore is provided to hold down the upper wall of the bag during the interval that the paste bar is being withdrawn. The presserfoot is urged in a radial direction by springs (9|, Figures 8, 9 and 10, housed in recesses in the ends of the cylinder 58 as indicated in Figure 14. The presserfoot is normally held by its springs a slight distance beyond the circumference of the cylinder ready to engage the bag as soon as it is in proper position. Just as the tucker blade has forced the bag bottom into the clamp, the presserfoot en gages the edge of 'the upper wall of the bag just below the paste line I90, Figure 16, and immediately afterward the paste bar applies the paste. The paste bar is then withdrawn but the presserfoot holds the wall of the bag down until the paste bar has been withdrawn sufficiently to become disengaged from the surface of the bag wall.

Due to the large size of the bottom of the bag made according to the present invention and to the close timing of parts, the presserfoot of the present invention differs slightly from that shown in my said application 537,844 in the following particulars. The bottom of the presserfoot is grooved at intervals, three grooves being shown, for instance, in Figure 14. Bent wires of small diameter I02 are secured by screws I03 on the back of the presserfoot and their bent ends lie in grooves in the presserfoot and pass through slots shown at I04 in the paste bar 18. These wires extend a little beyond the paste bar and insure suflicient engagement with the upper bag wall to avoid any danger of the wall following the paste bar as the latter is withdrawn.

The function of the auxiliary paste devices 92 is to put a spot of paste on each of the gussets 99 and these paste spots are shown at !05, Figure 16. The bottom of the bag is therefore not only pasted along the line Hill but the gussets themselves are pasted together at the points E05, thereby producing a more effectively sealed bottom.

On account of the large flap, the slits 6B are correspondingly of considerable length and with the ordinary former having the cut out portions 34a as indicated in Figure '7 there may be some danger of the edges of theslits getting caught at the forwardcorners of the notches 34a. In the present invention, therefore, I have provided two different ways whereby this difficulty may, be

overcome.

In Figures 5 and 6 a slightly modified former is shown. This is indicated by 39a. Instead of the notches 34a I provide cut-out portions I06 which are slightly within the edge leaving a smooth edge along which the bag tube can pass without danger. The feed rollers 34 in this modified form are spaced slightly closer together so as to coincide with the cut-out portions I06, otherwise the construction is just the same as previously described.

Instead of modifying the'former as just described, I may modify the slitter knives 10. In practice I have found it sufficient to make narrow saw cuts 101 spaced apart along the cutting edge of each slitter knife as indicated in Figure 4. The result of this modified slitter would be a cut in the paper which is not continuous but which consists of a series of short cuts with a very small portion of paper connecting them. When the slitter knife is so modified and the cuts which are designated as 68a are formed as shown in Figure 3, the usual former such as shown in Figure 7 may be used. It is to be understood that the connecting portions of paper between the short cuts 68a are so small that they are readily severed during the chopping operation.

In describing the upper pinch bar it was stated that the segment was relieved between the arcs 60 and 62. This may be done in several ways.

In Figures 8, 9 and 10 it is shown as a depression on a, shorter radius than that" of the arcs 60 and 62. In Figures 12 and 13, however, a modified method of relieving the pinch bar is shown. In Figure 12 the dotted arc llfla illustrates an arc of the radius equal to that of the arcs 60 and 62, while the solid line arc l I l is an arc of a slightly greater radius which becomes tangent to the arcs B0 and 62 as shown. In Figure 13 a similar method is used except that the arcs 60 and-62 are joined by flat portions H2 on either side of a.central flat portion H3. The form of pinch bar shown in Figures 12 or 13 provides for an easing of the pressure on the bag tube as it leaves and approaches the arcs 60 and 62 and suflicient friction is thereby created to hold the bag tube at all times under the control of the pinch bar.

therewith at this time.

Reference has been made to a frame supporting the gear 53. This frame consists of side members Hi0, Figure 2, and is supported in ways in the side members 2 of the main frame of the machine. The frame members M0 also carry the cylinders 55 and 58, the paste pot 90 and bag ejecting rolls llZa and H4.

The frame is adjustable to accommodate bags of different lengths. For such adjustment a rack M5 on each frame member 2, Figure 1, is engaged by a pair of pinions I 86 mounted on a shaft ll? rotated bylahand wheel l w."he, 7 a 7 To enable the gear 53 to constantly mesh with gear 52 for different positions of the frame, an arm M9 is supported for pivotal movement on shaft 55, said arm having an arcuate slot I20 and a bolt l2! passes through the slot and engages a frame member i it.

In describing the progress of the bag tube through the machine, reference has been made to the fact that at the time the bag tube is in the position shown in Figure 8, the upper wall of the tube is not at the proper angle in respect of the knife edge M to permit of severance, even if severance were desired. As a further protection against any scoring of the bag tube by the I teeth of the knife Ml, I provide a guard Mtb, Figures 8, 9 and 10, which guard extends from the base of the teeth back a short distance and projects slightly below the horizontal level of the edge of the teeth so that when the bag tube is in the position shown in Figure 8 and the tube is under tension, the guard engages the surface of the bag tube and prevents the teeth contacting When, however, the bag tube has been brought to the position shown in Figure 10, when severance of the tube must take place against knife M3, the wall to be severed is free from the guard and may engage the teeth without hindrance by the guard.

Several forms of pinch bars have been shown and in Figure 18 a somewhat different arrangement of pinch bar mechanism is shown more or less diagrarmnatically. Instead of having the arcs t0 and 62 carried by a single member such as 50, as shown in Figures 8, 9 and 10, these arcs may be arranged on separate members. In Figure 18 the roller tea, which corresponds to it, is shown as mounted on a shaft which has been designated 8a but corresponds to the shaft 8 of the other views. The upper roller carries a single segment a which corresponds in all respects to the are 603 of Figures 8, 9 and 10. There is also provided a second roller i Mi mounted on a shaft cut and creating a further slack between the time of making the firstand second cuts.

- 2. The process of making a long lip paper bag from a bag tube having substantially longitudinal slits therein of a length which determine the lip length, creating av slack in the tube, severing one wall of the tube along a line which meets one end of each slit, feeding the tube and subsequently severing the other wall along a line which meets the other end of each slit.

3. The process of making a paper bag which consists in making successive transverse cuts in the respective walls of a. bag tube having substantially longitudinal slits therein of a length which determine. the lip length, creating a slack in the tube prior to the first transverse cut and creating a further slack between the times of making the first and second cuts, the transverse cuts meeting the ends of the slits.

4. The process of making a paper bag which consists in making successive transverse cuts in the respective walls of a. bag tube having slits therein extending approximately in a longitudinal direction and of a length which determine the lip length, momentarily retarding the tube at the time of making the transverse cuts and permitting slippage of the tube between retardaa tions.

5. In a machine for making paper bags'having mechanism for forming a bag tube and having spaced transverse cutting edges for severing the walls of the tube to form individual bags; the combination with means for severing one wall of the bag tube, means for feeding the bag tube and means for subsequently severing the other wall thereof. l

6. In a machine for making paper bags, the combination with the means for forming a bag tube having slits therein of a length which determine the length of the closing flap of the finished bag; of transverse cutters spaced apart a distance less than the flap length, means for causing the respective bag tube walls to be successively presented to said cutters and means for feeding the tube betweensuccessive cuts.

7. In a machine for making paper bags, the combination with mechanism for forming a bag tube having substantially longitudinal slits in the edges thereof of a length which determine the length of the lip of the finished bag; of spaced. transverse cutters, means for creating a slack in the paper and simultaneously severing one wall of the bag by means of one of said cutters and means for creating further slack in the bag tube H5 and carrying a segment 62a correspon chng an'd'presenting the other wall of the bag in cutin all respects to the arc fifi of thefirst de scribed form. The roller lid is driven by gearing from a roller M0, the latter being geared to 66a by an intermediate gear 822.

The operation is precisely the same as previously described, the bag tube being momentarily retarded by the segment 50a at which time the lower wall of the bag tube is severed against the edge of the former. It will be noted that the segments- Glla. and 62a occupy different circumferential positions on their respective cylinders so that between the time that the bag tube is free of the segment 60a and before it is pinched by the segment 62a, slippage may occur as in the previously-described form.

What is claimed is:

1'. The process of making a paper bag which consists in making successive transverse cuts in the respective wall of a bag tube creating a slack in the tu prior to making t fi t a verse mechanism being so constructed and arranged ting relation to the other cutter.

8. In a bag machine, the combination with a former about which a web of paper is wrapped to form a bag tube, mean for feeding the tube and transverse cutting edges spaced apart in the direction of the feeding movement for severing the tube into bag lengths; of pinch bar mechanism arranged to retard the bag tube at periods in the formation of a bag length but permitting slippage of the tube between periods of the retardation. v

9. In a bag machine, the combination with a' former about which a web of paper is wrapped to form a bag tube, means for feeding the tube and transverse cutting edges spaced apart in the direction of the feeding movement for severing the tube into bag lengths; of pinch bar mechanism arranged to retard the bag tube at periods in the formation of a bag length, said pinch bar as to permit siippage oi the tube between of retardation but maintaining control of the bag tube during slippage.

10. In a bag machine, the combination with a former about which a web of paper is wrapped to form a bag tube, feed rollers for feeding the tubeand transverse cutting edges spaced apait in the direction of the feeding movement; of upper and lower pinch bars, the upper pinch her having its periphery so formed as to retard the bag tube at separated areas on the periphery thereof while permitting slippage of the tube between the retarding areas.

11. In a bag machine, the combination with a former about which a web of paper is wrapped to form a bag tube, means for feeding the tube and transverse cutting edges spaced apart in the direction of the feeding movement; of upper and lower pinch bars, one of said pinch bars its periphery formed so as to retard the bag at separated areas on the eriphery thereof, the portions of the pinch bar between the active areas being relieved to permit slippage of. the tube between the retarding areas.

12. In a bag machine, the combination with a former about which a web of paper is wrapped to form a bag tube; means for feeding the tube and transverse cutting edges spaced apart in the direction of the feeding movement; of a set of pinch bars spaced from each other, said pinch. bars being so timed as to act mccessiveiy to re tard. the bag tune.

oses 3. In a bag machine, the combination with a former about which a web of paper is wrapped to form a bag tube, means for the and transverse cutting edges spaced apart in the direction of the feeding movement; of a set of pinch bars spaced from each other, said pinch bars being so timed as to act successively to re tard the bag tube, and means for creating a slack in the bag tube between the periods of retardation.

ii. in a bag machine, the combination with a former about which a. web of paper is wrapped to form a bag tube, said former having a severing edge; of a second severing edge spaced from the severing edge of the former, means for feeding the bag tube adjacent said cutting edges, said second-mentioned edge having a attending below the horizontal plane of the travel oi the bag tube.

15. hi a bag machine, the combination with a former about which a web of paper is wrapped to form a bag tube, said former having notches in the edge thereof, feed rollers entering said notches for feeding the tube and transverse cutters for severing the tune transversely into hag lengths; of slitter knives for making cuts in the web prior to folding the same to form a tube, said slitter knives having cutting edges which. are interruptw at spaced intervals.

GEQEEQE PQPPE. 

